Characterization of electropenetrography waveforms for the invasive heteropteran pest, Halyomorpha halys, on Vicia faba leaves

The brown marmorated stink bug (BMSB), Halyomorpha halys Stål, has dispersed throughout the northern hemisphere, causing disturbances in agroecosystems and urban areas. Studies are, therefore, needed on the biology, physiology, and ecology of BMSB. This project characterized and partially correlated (via histology of plant tissues) the DC electropenetrography (EPG) waveforms related to non-probing (NP and Z) and both salivary sheath and cell rupture feeding. BMSB feeding behaviors were analyzed in comparison with the five other EPG waveform characterization papers published to date for heteropteran insects. Waveforms consisted of epidermal scanning (Hh1), pathway of stylets through leaf tissue (Hh2), X waves (Hh3), and sustained vascular ingestion (Hh4). In addition, a cell-rupturing phase in mesophyll (Hh2) and putative ingestion of resulting macerate (Hh5) were characterized. The most striking results were (1) the similarities of waveforms with other heteropterans, (2) performance of both sheath and cell rupture feeding strategies from all three plant cell types (xylem, likely phloem, and parenchyma macerate) on the same plant part, and (3) two different-appearing, dual-meaning X waves according to ingestion from xylem (Hh3a) or likely from phloem (Hh3b). This study provides a crucial framework for future, quantitative research on feeding behavior of this important invasive pest, to aid in the development of novel pest management tools.